Technical Field
Exemplary embodiments of the present invention relate to a capacitive sensing circuit for a multi-touch panel, and a multi-touch sensing device having the capacitive sensing circuit. More particularly, exemplary embodiments of the present invention relate to a capacitive sensing circuit for a multi-touch panel, which senses a capacitance in a multi-touch panel capable of multi-touch, and a multi-touch sensing device having the capacitive sensing circuit.
Discussion of the Related Art
As electronic engineering technology and information technology have repeatedly advanced, the importance of electronic devices in daily life including a work environment has been steadily increasing. In recent years, the types of electronic devices have diversified. In particular, in the field of portable electronic devices, such as mobile phones and Portable Multimedia Players (PMPs), a vast number of devices with new designs to which new functionalities have been added have been released almost every day.
As the types of electronic devices which people encounter in daily life have gradually diversified and the functionalities of electronic devices have become advanced and complicated, there has been an urgent need for a user interface which users can easily learn and which can be manipulated intuitively. Touch screen devices have attracted attention as input devices capable of meeting such a need, and have already been widely applied to a variety of electronic devices.
Particularly, a touch screen device, which is the most general application of such a touch panel device, is referred to as a device which detects the position of touch generated by a user on a display screen, and performs general control on electronic equipment as well as the control of a display screen using information about the sensed touch position as input information. Further, with the popularization of such a touch screen device, when a touch screen is manipulated, the importance of a touch screen capacitance measurement circuit and a capacitance controller semiconductor which is in charge of the circuit has increased.
Meanwhile, noise components are included in a signal for sensing a contact position of a human body in a touch panel. In order to increase touch sensitivity by enhancing a signal-to-noise ratio (SNR), noise components included in the signal should be removed. Conventionally, it is easy to remove high frequency noise components from noise components of the signal by using filters. However, it is difficult to remove low frequency noise components from noise components.